Printing systems or printers are used to facilitate the printing of hard copies, of electronic documents stored or prepared on user devices, for personal, business, or administrative purposes. Examples of user devices may include workstations, personal computers, personal digital assistants (PDAs), laptop computers, notebooks, smart phones, and the like. The printers can directly communicate with the user devices, or can communicate with the user devices over a network.
Generally, a user can submit a print job to the printer in the form of page description language (PDL) file from any of the user devices connected to the network. The print job can be submitted either by using a printer driver or by using a driverless web-based platform. The printer driver is normally associated with only one printer; however, the web-based platform is normally associated with all the printers connected to the network.
At the printer, a raster image processor (RIP) receives the PDL file having an input image. In an example, the input image may include one or more objects such as characters, words, text, and other objects such as graphics, images, etc. The PDL file received at the RIP includes rendering information describing the layout of the input image as it was created on the user device used by the user. Also, the RIP makes the decision on how to process the input image based on the rendering instructions stored in the PDL file. On the basis of the decision, the RIP converts the input image from their form in the PDL file to a sequence of serial instructions for the printer in a process commonly known as “ripping” and provides a ripped image to an image storage-and-retrieval system known as a print engine. The print engine converts the ripped image into a ready-to-print (RTP) format and makes it available to the printer for printing the input image.
However, while the making the input image available to the printer, the user of the user device is provided with limited option of enhancing the color or image quality of the input image. For example, the user is generally provided with options of selecting settings such as lighting/darkening of the input image with reference to background. In this relation, various efforts regarding printers or printing system have been made in past for continuing developments to improve the image quality. One of such effort includes implementation of the various quality enhancement operations on the objects present in the input image for image quality enhancement. For example, for enhancing the quality of the input image, the enhancement operations enable the user for selecting object clear for an image (not tagged as clear in PDL) followed with the selection of flood clear for that image. With such selections, the image will be rendered using cyan, magenta, yellow, and black (CMYK) profile with clear plane in addition. This is because the image was not tagged as clear in the PDL so obviously it will assume CMYK value. However, in such efforts, the objects (text/graphics) that are tagged as clear objects become invisible in case the user applies flood clear on the object tagged as clear in the PDL. Flood clear is a feature of printing systems in which the entire page or area on an input image has clear ink effect. Thus, when the user selects the application of the flood clear feature on the object tagged as clear in the PDL, the printer or the printing system facilitates by default the highest precedence to the flood clear, so that the said object tagged as clear will have only clear value and no CMYK value, as the object is tagged as clear in the PDL, and as the amount selected for flood and the same amount of clear will be applied throughout the plane. Because of such precedence of the application of the flood clear over the object clear, the object tagged as clear in the PDL goes invisible.
Accordingly, there is a need for having a technique to modify the values of the pixels associated with clear objects so that the clear objects can be visualized by human eyes even after the application of the flood clear.